Albert Einstein said that communication puts your education at your disposal. If you can't express yourself, what use is your knowledge? Communication skills are essential for confidence and leadership.
If you're terrified to speak in front of a group, join Toastmasters. The End ... or rather, The Beginning.
If you think you're already good, join to get better and help others.
This podcast accompanies a blog post at Riscario Insider: http://blog.riscario.com